Air cushion system for aircraft removal

ABSTRACT

Apparatus and method for quick conversion of a disabled aircraft or other structure to a ground effects machine includes the use of a flexible skirt conforming to the periphery of the structure and adhesive strip means for attachment of the skirt at the top edge thereof. At the bottom edge of the skirt, laterally extending cross ties hold the lower edge inwardly to provide a captive air space, said air space being defined by the lower portion of the aircraft and the skirt. Superatmospheric air supply is provided to the space from the fan jet portion of an engine of the aircraft through an annular collector, a transfer tube and a peripheral manifold on said skirt. The manifold is substantially tear shaped in cross section and assists in holding the strip means against the surface of the structure and isolated from peeling forces and transient pressure changes in the air space. Alternatively, V-shaped adhesive tape formed with upwardly and downwardly flaps holds the top of the skirt so as to resist peeling. Crawler tube means are provided to extend the stabilizing cross ties beneath the aircraft for attachment and high strength contact adhesive tape or epoxy resin is utilized to form the adhering strip.

United States Patent [191 Muller 51 Apr. 10, 1973 AIR CUSHION SYSTEM FORAIRCRAFT REMOVAL [76] lnventorz Albert F. Muller, 400 Scott Street,

Baytown, Tex. 77520 [22] Filed: Dec. 2, 1970 [21] Appl. No.: 94,312

[52] C1. ..244/2, 244/23, 244/100, 244/139, 180/124, 180/127 [51] Int.Cl ..B64c 37/00 [58] Field of Search ..244/2, 23, l, 139, 244/100;180/124, 127

[56] References Cited UNITED STATES PATENTS 3,072,930 l/1963 Fraehel..'9/11 A 3,155,992 11/1964 Shewmake etal ..9/ll A 3,520,381 7/1970Pinder 1 80/127 3,502,168 3/1970 Jones ..l80/l27 FOREIGN PATENTS ORAPPLICATIONS 7 272,359 1/1965 Australia .,.l80/l27 1,556,009 1/1970Germany 180/127 OTHER PUBLICATIONS Hovering Craft and Hydrofoil,Kalerghi Publications, Volume 6, Number 1 1, August 1967, Pages 14-16.

Primary Examiner-Milton Buchler Assistant ExaminerCurt A. RutledgeAtt0meyLowe and King [57] ABSTRACT Apparatus and method for quickconversion of a disabled aircraft or other structure to a ground effectsmachine includes the use of a flexible skirt conforming to the peripheryof the structure and adhesive strip means for attachment of the skirt atthe top edge thereof. At the bottom edge of the skirt, laterallyextending cross ties hold the lower edge inwardly to provide a captiveair space, said air space being defined by the lower portion of theaircraft and the skirt. Superatmospheric air supply is provided to thespace from the fan jet portion of an engine of the aircraft through anannular collector, a transfer tube and a peripheral manifold on saidskirt. The manifold is substantially tear shaped in cross section andassists in holding the strip means against the surface of the structureand isolated from peeling forces and transient pressure changes in theair space. Alternatively, V-shaped adhesive tape formed with upwardlyand downwardly flaps holds the top of the skirt so as to resist peeling.Crawler tube means are provided to extend the stabilizing cross tiesbeneath the aircraft for attachment and high strength contact adhesivetape or epoxy resin is utilized to form the adhering strip.

19 Claims, 9 Drawing Figures PATENTED 3,726,493 sum 2 or 2 I nWEA/raie,

4155675 Mums/e AIR CUSHION SYSTEM FOR AIRCRAFT REMOVAL The presentinvention relates to ground effects machines and, more particularly, toa method and apparatus for conversion of a disabled aircraft or otherstructure to such a ground effects machine.

BACKGROUND OF THE INVENTION The trend today in the aircraft industry isto manufacture larger and larger ships to carry more and more passengersor cargo. The present-day pinnacle of this development is represented bythe CSA transport aircraft manufactured by Lockheed-Georgia Company, aDivision of Lockheed Aircraft Corporation for the US. Air Force and theBoeing 747 passenger aircraft manufactured by the Boeing Company,Seattle, Wash. The gross weight of these behemoths of the modernaircraft age is presently up to a staggering 750,000 pounds and plansare now being made for even greater weights and payload capability.

Since the advent of these aircraft, the problem has arisen of having tocrash land or land gear-up of these large aircraft at one of thenationss major or other civilian or military airports and then not beingable to reopen the runway within a reasonable time. In short, prior tothis invention there has not been provided in the art a system or methodthat is capable of quick removal of the aircraft from a runway when sucha large aircraft is disabled. Such a situation would require that therunway on which the disabled aircraft is positioned be closed for aninordinate length of time, up to four days or more, while mechanicslaboriously jack up the aircraft and position supporting dolliesunderneath sothat the aircraft may be towed to a repair site. Thus,there is a need today for a system and method for removal of these largeaircraft from the runway within a few hours time so that the runway maybe quickly placed back in service to handle the other air traffic.

OBJECTIVES OF THE INVENTION Accordingly, it is one object of the presentinvention to provide a method and apparatus for quickly converting adisabled or immobile structure, such as an aircraft, to a ground effectsmachine whereby the same may be lifted and moved.

. It is another object of the present invention to pro-- provide a skirtfor conversion to a ground effects machine that is attached to anaircraft or the like without permanent damage to the'aircraft skin andmay be readily removed after use.

It is still another object of the present invention to provide a groundeffects skirt with an integral manifold that assists in maintaining theadhering strip in firm face contact with the skin, or alternatively aV-shaped tape, to resist peeling during operation.

BRIEF DESCRIPTION OF THE INVENTION Briefly considered and in simplifiedform, the present invention envisions conversion of a disabled aircraftor other immobile structure, such as a house, large tank, largeocean-going ship or the like, to a ground effects machine to allow thesame to be easily moved over any reasonably flat terrain, such as land,swamp land or even water. The heart of the conversion apparatus is theutilization of a flexible skirt capable of conforming to the outerconfiguration of the aircraft and attached to the aircraft bysurface-adhering strip means. at the top edge of the skirt. Similarly,the heart of the inventive method is concerned with adhesively adheringthe upper edge of the flexible skirt to the aircraft to form the captiveair space below, and then pressurizing the space to provide the liftingcushion for supporting the aircraft. The strip means, which may take theform of epoxy resin or high-strength adhesive tape, provides formaterial is preferably selected to give the lightest weight-and greateststrength and servicability, and such synthetic materials as nylon,dacron, Teflon, polypropylene and Fiberglas are deemed suitable for thispurpose. The lower edge of the skirt is held inwardly to spanapproximately nine-tenths of the aircrafts width by installing laterallyextending cross ties (at intervals about equal to the fuselage width).The

cross ties are initially extended by a crawler tube that engages betweenthe bottom of the aircraft and the ground. Rotating means for the tubeis provided in the form of a motor and coupling mounted on a skidplatform for movement with the tube.

. A peripheral manifold formed integrally with the skirt directsopenings inwardly around the full periphery to distribute the air supplyfrom an outside pressure source. The inside of the manifold is formed bya flexible wall that lies in face-to-face contact with the outer surfaceor skin of the structure and thereby isolates the adhesive strip meansfrom sudden pressure changes in the supporting air space, and assists inholding the adhesive strip against the surface to prevent initiation ofany peeling action of the strip from the surface thereby improving thepeel strength of the joint. If desired, the adhering strip, andparticularly contact sensitive adhesive tape if used, may have increasedwidth (approximately equal to the height of skirt) in the form ofintegral, upwardly and downwardly extending holding flaps so that thepotential peeling force at the top of the skirt is translated to apulling force over a greatly enlarged surface area thereby virtuallyeliminating the peeling problem. A triangular separation space ismaintained at the juncture of the flaps to allow assumption orapproximation of a tangential relationship.

of the flaps with skin of the structure to accomplish this result.Preferably, the air pressure source is gained from the fan outlet nozzleof the nacelle of a fan jet of the aircraft itself through an annularcollector and connected transfer tube.

In the case of a crash landed aircraft, the lower portion of thefuselage will most likely have openings therein resulting from theunprotected engagement with the runway pavement. According to anotherfeature of this invention, these openings are not attempted to berepaired, but the entire interior of the aircraft is pressurized withany openings in the upper portion of the aircraft being patched topreclude the escape of air therefrom. Tugs are attached to the wingtie-down points to move and steer the aircraft after the supportingcushion is formed.

Still other objects and advantages of the present invention will becomereadily apparent to those skilled in this art from the followingdetailed description, wherein I have shown and described only thepreferred embodiment of the invention, simply by way of illustration ofthe best mode contemplated by me of carrying out my invention. As willbe realized, the invention is capable of other and differentembodiments, and its A flexible skirt is attached at its upper edgeseveral details are capable of modification in various obvious respects,all without departing from the invention. Accordingly,t he drawings anddescription are to be regarded as illustrative in nature, and not asrestrictive.

DESCRIPTION OF THE DRAWINGS FIG. 3 is a perspective layout view of theflexible I skirt illustrating the adhesive adhering strip and thedistributing manifold;

FIG. 4 is a cross-sectional view taken along line 4--4 of FIG. 3 showingthe passage of air into the air space forming the air cushion;

FIGS. 5 and 5a are enlarged cross-sectional views of two alternatives ofthe flexible skirt, manifold and adhering strip combination; p

FIG. 6 is a cross-sectional view showing the crawler tube and drivingmeans of the conversion kit for initially extending the cross linesunder a crashlanded aircraft; and 1 FIG. 7 is a cross-sectional viewtaken along line 7-7 of FIG. 6 showing the drive motor for the crawlertube and the supporting skid.

' DETAILED DESCRIPTION OF THE INVENTION With reference now toFlG. l ofthe drawings and relating this figure to FIG.'2,one particularapplication of the conversion kit of the present invention and theassociated method has been illustrated and may be considered as thepreferred embodiment. In this embodiment, the structure being moved is adisabled transport aircraft, generally designated by the referencenumeral 10, and as will be recognized by those skilled in the art may beone of the Lockheed built (35A transport airthe lower edge of the skirtbeing in juxtaposition (operative relationship) with ground or runway G.It will be noted in FIGS. 1 and 2 that the skirt 15 is preferablyattached so as to be at substantially the same height H around the fullperiphery of the fuselage F.

As shown in FIG. 1, the aircraft 10 in the air-cushion supportedcondition is closer to the ground G than it would have been if thelanding gear 16, 17 (shownin dotted line outline) had been employed toland the aircraft. In this condition, the aircraft is thus capable ofbeing moved in accordance with the invention since the frictionalengagement between the fuselage F and the ground Ghas been relieved.However, it should be understood that the skirt 15 could besatisfactorily attached and made to support the fuselage F when theaircraft has crash landed in other positions (other than idealconditions), such as when the aircraft lands with one gear up and thefuselage F thus resting at an obliqueangle to the ground G. All that isnecessary is that the lower edge of the skirt l5'be brought intojuxtaposition to the ground G so that the air cushion may be formed andmaintained. To do this, the skirt 15 may be attached at a differentheight H with respect to the fuselage than the other side. In this case,the maintenance of balance of the aircraft is more critical and must bemaintained during'subsequent removal movement by outside forces, such asby tow lines and/or by only partial lifting sufficient to reduce but noteliminate frictional engagement of the aircraft with the ground.

When inflated to the operative position, the sides of the skirt 15 arebowed outwardly by the air cushion, as can be seenin these two Figures.The actual supply of air to air-cushion space S, defined by the lowerportion or belly of the aircraft l0 and the skirt 15, is provided by atransfer tube 18; it being understood that additional tubes could beemployed if needed. At the inlet v end of the tube 18, an annularcollector collar 19 is provided to receive compressed air from thenacelle of the aircrafts engine 20.

As shown in FIG. 2a, this annular collar 19 is attached onlyto the fanportion of the engine 20, as depicted by the fan blades 21, shown indotted line outline in this Figure. The hot gas exhaust of the engine 20is represented by the opening 22 with final stage tur- I bine blades 23being visible therein. Since none of the craft. Thus, while thepreferred embodiment will be hot combustion gases are transferred to theair cushion space S beneath the aircraft 10, no problem of overheatingor the need for expensive heat resistant materials for the components ofthe kit is necessary.

In FIG. 3, the skirt 15 isshown in perspective view without the aircraft10 that it is intended to support. As can be seen, the peripheral loweredge of the skirt 15 is held so as to be directed inwardly (see FIG. 4)by a plurality of cross lines or ties 25. These cross lines may besuitably attached to the lower edge by tabs 26, 27 and for optimum skirtstability and control the tips of the lower edge are spaced a distance Xapart that is approximately percent of the width of the aircraftfuselage F, as shown in FIG. 4.

At the top edge of the skirt 15 a surface adhering strip 30 is appliedand forms an important feature of the present invention. This strip 30may be in theform of an epoxy resin layer, that securely bonds the skirt15 around the full periphery of the fuselage F for continuous attachmentand sealing of this top edge. Because of this feature of adhesivelyadhering the skirt to the aircraft 10, the fuselage F does not have tobe penetrated for attachment of fasteners. This means that the skirt 15may be removed from the vehicle after use without permanent damage tothe skin thereof, thus holding the required maintenance work to rebuilda crash landed aircraft to a minimum. All that needs to be done in mostcases to remove the skirt 15 is to apply a solvent to the adhesive strip30 thereby leaving the clean skin of the aircraft.

As best shown in FIGS. 4 and 5, the pressurized air supply receivedthrough transfer tube 18 is distributed around the full periphery of theskirt 15 through a manifold 35. The manifold in effect is integral withthe top portion of the skirt 15 and includes an inner peripheral wall 36having a plurality of nozzle openings 37 therein. While not shown, itshould be understood that these openings may be graduated around theperiphery towards smaller openings as the proximity of the transfer tube18 is approached, as is common practice in air distribution systems. Thesupplying of air through a manifold 35 around the periphery is importantin this environment since blasts of air against the ground and excessiveturbulence at the intake area tending to cause skirt flutter anddisruption of the seal around the lower edge is avoided.

In FIG. 5, the peripheral wall 36 is shown as attached to the skirt 15in any known manner such as by upper and lower layers or joints38 ofhigh strength adhesive. If desired, mechanical fasteners 39 or sewingmay be employed as an alternative, or as an additional means, to formthe seal and to assure against separation at these joints.

In order to reduce the mechanical load on the adhering strip 30 and todistribute the load across the full width of the strip, the manifold 35is formed so as to assume a substantially tear shape in cross sectionwith the interior peripheral wall 36 being at least partially contiguouswith and in sealed relationship with the outer surface or skin of theaircraft 10, as shown in FIGS. 4 and 5; The air pressure in the manifold35 is slightly greater than the pressure in the air cushion space S dueto the loss experienced in passing through the nozzle openings 37, thusassuring the tear shaped configuration and the contiguous relationshipduring normal operation. During start-up, the manifold 35 is pressurizedfirst to form the seal, however the tear shape is maintained andballooning avoided by the presence of the cross ties and the immediatelyfollowing occurrence of filling of the space S. This relationship andfea ture of the invention effectively isolates the strip 30 from anytransient increases in pressure in the space S that might be caused by asudden shift of the aircraft 10, such as might occur by completelyclosing off the slight air-escape area between the lower edge of theskirt l5 and the ground G. The laying of the wall 36 flat against theaircraft surface also assures that a peeling of the strip 30 startingfrom the inside or leading edge of said strip is effectively minimizedsince there is no angle to start a peeling action at this point. Inother words, the force is effectively transferred over the full width ofthe strip 30 rather than being limited just by the leading edge so thatin effect a shearing (as opposed to peeling) of the strip 30 is requiredbefore separation can occur. This means that an adhesive with less stringent requirements for peel strength may be used than would otherwise berequired, and reliance may be put instead on the lap shear strengthof-the adhesive which is normally several times higher (for example acoefficient of 3,000-4,000 lbs/in. as opposed to -l25 lbs/in. fortypical high strength epoxy resins).

As mentioned above, epoxy resins may be selected for the sealing areasat the strip 30, and at the joints 38. There has been wide acceptance ofthese adhesives in the aircraft industry because of their simplicity ofuse, and their superior holding strength on aluminum and other material.For example, reference may be made to the publication entitled EpoxyResins by Irving Skeist, Reinhold Publishing Corporation, New York,Copyright 1960, and in particular Chapter 10 commencing at page therein.Also, I have investigated particular epoxy resins, such as those shownand described in U.S. Pats. No. 3,477,966 issued Nov. ll, 1969 toPhillips Petroleum Company and No.

3,525,779, issued Aug. 25, 1970 to Dow Chemical Company and find thatsufficiently high peel and lap shear strength properties are exhibitedfor these particular resins to allow successful utilization inperformance of the teachings of my invention.

Although known surface contact adhesive tapes have somewhat lessstrength than the epoxy resins, successful use of these is possible whenminimizing the necessity for high peel strength by the special tearshape configuration of the manifold 35', thus effectively isolating thestrip 30 from excessive forces as noted above.

In FIG. 5a is shown an alternative arrangement wherein the adheringstrip assumes the form of adhesive tape having greatly extended width,as compared to the strip 30, and preferably equal to at leastapproximately the height of the skirt 15. Of importance is that the tapeincludes a flap 40 extending downwardly along and in contact with thefuselage F of the aircraft so as to form the interface between the skinof fuselage and the pressurized space S. The tape is thus firmly held incontact with the skin by the increased pressure within the space S andthere is no peel angle formed at the leading line of contact. Note pointP of the flap 40 in FIG. 5a, that is, in this case actually the point oftangency with the curved fuselage F, forms no angle; i.e., there issubstantially 0 between the attached and unattached portions of theflap. Because of the extended area of contact and there being no peelangle, potential peeling force is translated into tangential pullingforce thereby rendering the much higher lap shear strength (lap shearcoefficient X area of contact), the limiting factor as to strength ofthe joint.

The tape preferably also extends upwardly with a flap 41 to form the topof the skirt 15. A triangular shaped space 42 is formed at the juncturebetween the flaps so that the tape is V-shaped with the pulling forcebeing directed toward the juncture virtually eliminating the tendency ofthe contact seal area to peel away.

Suitable contact sensitive tapes having sufficient lap shear strengthare readily available, such as those tapes.

shown in U.S. patents Gorman, U.S. Pat. No. 3,479,311, issued Nov. 18,1969, and Grossman et al., U.S. Pat. No. 3,508,949, issued Apr. 28,1970.

The manifold 35a is separately formed in the embodiment of FIG. a and afolded over portion sewn or fastened by fasteners 39a to the skirt l5and the tape.

The overlapped edges of the manifold 35a may be sewn together but remainloose from the tape.

As to the materials to be used for the other components of theconversion kit as heretofore described, the skirt itself may be aflexible canvas or other cloth, preferably fabricated of relativelyhigh-strength, light weight fibers, such as nylon, dacron, polypropyleneor Fiberglas. The cloth is covered or blinded off by a flexible plasticcoating, such as a plastic base paint, so as to make the samesubstantially impervious to the passage of air. In certain instances,the spraying of water or other liquid on the skirt may be used tosufficiently block the pores of the fabric to.

maintain the air cushion in tact, or in other cases, water may be usedor treated skirts to increase the efficiency of the sealing, as may berequired by greater than design loads being lifted. The strength of theskirt 15.

should be such as to withstand a force of 180 pounds per inch with onlymoderate stretching, which is within the state of the art of the abovematerial. The cross lines 25 are preferably fabricated of metal toprovide limited stretching, to prevent cutting by ragged edges of theplane and deleterious abrading by the concrete runway and should becapable of withstanding a pull of about 8,000 pounds. The cross linesare preferably positioned at equal intervals about equal to the fuselagewidth along the length of the fuselage F, as shown in FIGS. 1-3. Thecross lines 25 give and. maintain the bulged out shape of the skirt 15for stability and to maintain the lower sealing edge along the ground Gto prevent skirt flutter and loss of the air cushion. Bowshapedreinforcing or shaping ribs 31 may be provided if desired in conjunctionwith the cross lines 25 to lend body to the skirt 15 and to encourageformation of a proper shape of the skirt 15 especially when start-up ofthe air cushion system occurs.

Another important feature of the conversion kit and method of thepresent invention is concerned with the initial extension of the crosslines 25' underneath the fuselage F ofthe disabled aircraft 10 by meansof a crawler tube 45, as shown in FIG. 6. The cross line 25 is placedinside the tube 45 and attached to the forward end thereof. The spiralthread 46 on the exterior of the tube 45 allows effective engagementwith the fuselage F and the ground'G to cause the tube 45 to crawlforwardly under the fuselage F even though there is originally maybe nospace.

To rotate the tube 45, a motor assembly 50 maybe provided includingmotor 51, a worm and pinion drive gear combination 52 and a drivecoupling 53, as shown in FIGS. 6 and 7. The motor assembly 50 ispreferably mounted on a support skid 54 so that upon advance of the tube45 the driving motor may follow as necessary. If required, outriggerhandles 55 may be provided on both sides of the skid 54 in order toapply an effective force to counteract the turning moment during forwardand reverse direction operation, as noted by the force arrows in FIG. 7.

After the line has been extended under the structure, the ends areattached to the corresponding tabs 26, 27 to stabilize the skirt asindicated above. The crawler tube 45 may remain on the line 25 duringthe operation of the air cushion device. However, if desired, theforward end of the line 25 may be simply removed from its attachmentwith the tube 45 and the motor assembly 50 driven in the reversedirection to withdraw the tube whereby it can be utilized to extend theother lines 25. If individual tubes 45 remain under the aircraft 10 witheach cross line, the coupling 53 is simply released from the tube 45 atthe end of the forward driving action.

In operation, the crash landed aircraft 10 is first measured around theperiphery and a height H above the ground G established and markedaccordingly. The epoxy resin strip 30 is next applied around the perime-I ter of the aircraft 10 in accordance with the marking and directly onthe skin of the fuselage F. As this is performed, a workman followsbehind laying the upper edge of the skirt 15 on the strip 30 and thenthe edge is suitably held in position the required time for curing.After the skirt 15 has been mounted around the full perimeter of thefuselage F, a suitable connection of the two ends (not shown) is made.The annular collector collar 19 is applied to the nacelle of thedisabled aircraft and the transfer tube 18 is connected to the skirt 15in the proper manner. It should be noted at this point that the sourceof air pressure may be alternatively taken from a sister aircraft oreven from other sources, such as separate compressors in accordance withthe broad teachings of the present invention.

Next, initial air pressure is preferably provided to the space Sunderneath the fuselage F to check for leaks around the perimeter of thestrip 30. With respect to the openings ripped in the bottom of thefuselage F by the crash landing, no attempt has been made to repairthese, but instead the interior of the aircraft is allowed toibepressurized. Then during this initial pressurizatiorl, all doors andother openings are checked for assurance that the upper portion of thefuselage F- is now tightly sealed off. Any rips in the upper portion ofthe fuselage F may be temporarily patched with epoxy resin and treatedcloth ofthe type used for the skirt 15. A'pair of tugs T1, T2 areattached by lines to the wing tie-down or hard points, as shown in FIG.2. The system is ready for thelifting and moving operation.

The jet engine 20 is now powered at sufficient spee to cause theaircraft 10 to be lifted and supported on an air cushion. In the case ofa CSA transport, approximately 2.5 p.s.i.g. accomplishes this purposeand powering of the engine at slightly greater than idle speed has beencalculated to give the necessary air supply. Once the aircraft issupported on the air cushion, the tugs T1, T2 are used to steer andmaneuver the aircraft 10 to remove the same from the runway and to arepair site. By drawing the lines on the tugs T1, T2 taut, the balanceof the aircraft may be maintained in an advantageous manner, which isparticularly important when the aircraft 15 has landed in other than atotal upright position.

In summary, it can be seen that a simple, inexpensive conversion kit andmethod has been provided to allow quick removal of aircraft from runwaysafter the aircraft has crash landed and is disabled. The skirt 15 isattached directly to the fuselage F by an adhering strip 30 and crosslines 25 stabilize the skirt to form an air cushion in the space S toallow supporting of'the aircraft 10. The peripheral manifold 35 allowsdistribution of the air pressure supply around the perimeter of thefuselage F and because of its unique tear shape isolates the strip 30 togain special advantages in terms of reducing the requirements for peelstrength and allowing reliance on the lap shear strength. The air supplyis conveniently gained directly from the fan jet portion of theaircrafts engine 20 and steering, balancing and movability is providedby conventional tugs T1, T2. Thus, with this system the necessarycomponents may be prepositioned or quickly flown in to any airfield inthe world, the kit attached to the aircraft and the aircraft removedfrom the runway so that the airfield may be opened to other air trafficwithin a matter of hours, either in peace time or in critical war timesituations. Further, no appreciable space is required between thefuselage F and the ground G to install the inventive system, such as isrequired when supporting an aircraft on separate ground effects machinesknown as air barges, and no permanent damage is done to the fuselage byadhesively adhering the skirt thereto thus greatly reducing therebuilding requirements for the aircraft 10.

In this disclosure, there is shown and described only the preferredembodiment of the invention,.but, as aforementioned, it is to beunderstood that the invention is capable of use in various othercombinations and environment and is capable of changes or modificationswithin the scope of the inventive concept as expressed herein.

I claim:

I. A kit for quick conversion of an immobile, large aircraft-sizestructure to a ground effects machine comprising a flexible skirtcapable of conforming to the outer configuration -of said structurearound the periphery thereof, surface-adhering strip means forcontinuous adhesively attaching and sealing of the top portion of saidskirt to said structure, means for holding the lower edge of said skirtin juxtaposition tothe ground and directed inwardly to provide a captiveair space defined by the lower portion of said structure and said skirt,and air pressure means for introducing a superatmospheric air supply tosaid space to provide a lifting force for supporting said structure.

,2. The conversion kit of claim 1 wherein, said air pressure meansincluding a manifold extending around the periphery of said skirt andhaving inwardly directed openings to distribute the air supply, anoutside pressure source, and an air transfer tube connecting saidmanifold -and said outside pressure source,- said manifold being formedalong the inside of said skirt and positioned below and adjacent saidstrip means.

3. The conversion kit of claim 1 wherein said pressure source includes afan jet, an annular collector collar mounted over the fan outlet portionof the nacelle of the jet to receive the cool pressurized air andtransfer the same to said inlet tube.

4. The conversion kit of claim 1 wherein said strip means comprises ahigh-strength contact adhesive tape including a flap extendingdownwardly from said top portion of said skirt and forming the'interface between said space and said structure, said flap beingconnected to said structure so as to form no peel angle to permitreliance on the lap shear strength of said tape.

5. The conversion kit of claim 4 wherein said strip means furthercomprises an upwardly extending flap forming the top portion of saidskirt, said upwardly extending flap being connected to said structure soas to form no peel angle to permit reliance on the lap shear strength ofsaid tape.

6. The conversion kit of claim 5 wherein said flaps .forrn asubstantially V-shaped juncture spaced from said surface.

7. The conversion kit of claim 1 wherein said strip means is readilyremovable from said structure after use without permanent damage to theskin thereof.

8. The conversion kit of claim 1' wherein said strip means comprises ahigh-strength epoxy resin.

9. A kit for quick conversion of an immobile structure to a groundeffects machine comprising a flexible skirt capable of conforming to theouter configuration of said structure around the periphery thereof,surfaceadhering strip means for continuous attachment and sealing of thetop portion of said skirt to said structure, means for holding the loweredge of said skirt in juxtaposition to the ground and directed inwardlyto provide a captive air space defined by the lower portion of saidstructure and said skirt, and air pressure means for introducing asuperatmospheric air supply to said space to provide'a lifting force forsupporting said structure, said holding means including cross tiesextending laterally across said structure and interconnected to thelower edge of said skirt.

10. The conversion kit, of claim 9 wherein is further provided crawlermeans for initially extending said cross lines underneath saidstructure.

11. The conversion kit of claim 10 wherein said crawler means includes atube through which a cross line passes,- spiral thread means on saidtube for operative engagement with the bottom of said structure and saidground, and means to rotate said tube to provide crawling action.

12. The conversion kit of claim 11 wherein said means to rotatecomprises a motor, coupling means to connect said motor and said tube,and a skid platform for mounting said motor for movement with said tube.

13. A kit for quick conversion of an immobile structure to a groundeffects machine comprising a flexible skirt capable of conforming to theouter configuration of said structure around the periphery thereof,surfaceadhering strip means for continuous attachment and sealing of thetop portion of said skirt to said structure, means for holding the loweredge of said skirt in juxtaposition to theground and directed inwardlyto provide a captive air space defined by the lower portion of saidstructure and said skirt, and air pressure means for introducing asuperatmospheric air supply to said space to provide a lifting force forsupporting said structure, the inside of said manifold being formed by aflexible wall, said manifold being substantially tear-shaped in crosssection when inflated and at least partially contiguous in sealedrelationship with the outer surface of said structure, whereby saidstrip means is isolated from sudden pressure changes in said space andheld flat against said surface to resist peeling.

14. The method of quick conversion of immobile, large aircraft-sizestructure to a ground effects machine comprising the steps of adheringby strip means theupper portion of a flexible skirt directly to theouter peripheral surface of said structure, holding said skirt so thatthe lower edge of said skirt is in juxtaposition to the ground, wherebyto form a captive air space defined by the lower portion of saidstructure and said skirt, and then pressurizing said space with asuperatmospheric air supply to provide a lifting force for supportingsaid structure.

15. The method of conversion of claim 14 further including the step ofpressurizing the interior of said structure through openings in saidlower portion communicating with said air space, and patching anyopenings in the upper portion of said structure to preclude the escapeof air therefrom.

16. The method of conversion of claim 15 wherein the structure is anaircraft and further including the step of attaching control lines tothe wing tie-down 4 the adhering step is performed by applying anadhesive tape.

19. The method of conversion of claim 18 wherein the step of applyingthe adhesive is performed only by pressure contact.

1. A kit for quick conversion of an immobile, large aircraftsizestructure to a ground effects machine comprising a flexible skirtcapable of conforming to the outer configuration of said structurearound the periphery thereof, surface-adhering strip means forcontinuous adhesively attaching and sealing of the top portion of saidskirt to said structure, means for holding the lower edge of said skirtin juxtaposition to the ground and directed inwardly to provide acaptive air space defined by the lower portion of said structure andsaid skirt, and air pressure means for introducing a superatmosphericair supply to said space to provide a lifting force for supporting saidstructure.
 2. The conversion kit of claim 1 wherein, said air pressuremeans including a manifold extending around the periphery of said skirtand having inwardly directed openings to distribute the air supply, anoutside pressure source, and an air transfer tube connecting saidmanifold and said outside pressure source, said manifold being formedalong the inside of said skirt and positioned below and adjacent saidstrip means.
 3. The conversion kit of claim 1 wherein said pressuresource includes a fan jet, an annular collecTor collar mounted over thefan outlet portion of the nacelle of the jet to receive the coolpressurized air and transfer the same to said inlet tube.
 4. Theconversion kit of claim 1 wherein said strip means comprises ahigh-strength contact adhesive tape including a flap extendingdownwardly from said top portion of said skirt and forming the interfacebetween said space and said structure, said flap being connected to saidstructure so as to form no peel angle to permit reliance on the lapshear strength of said tape.
 5. The conversion kit of claim 4 whereinsaid strip means further comprises an upwardly extending flap formingthe top portion of said skirt, said upwardly extending flap beingconnected to said structure so as to form no peel angle to permitreliance on the lap shear strength of said tape.
 6. The conversion kitof claim 5 wherein said flaps form a substantially V-shaped juncturespaced from said surface.
 7. The conversion kit of claim 1 wherein saidstrip means is readily removable from said structure after use withoutpermanent damage to the skin thereof.
 8. The conversion kit of claim 1wherein said strip means comprises a high-strength epoxy resin.
 9. A kitfor quick conversion of an immobile structure to a ground effectsmachine comprising a flexible skirt capable of conforming to the outerconfiguration of said structure around the periphery thereof,surface-adhering strip means for continuous attachment and sealing ofthe top portion of said skirt to said structure, means for holding thelower edge of said skirt in juxtaposition to the ground and directedinwardly to provide a captive air space defined by the lower portion ofsaid structure and said skirt, and air pressure means for introducing asuperatmospheric air supply to said space to provide a lifting force forsupporting said structure, said holding means including cross tiesextending laterally across said structure and interconnected to thelower edge of said skirt.
 10. The conversion kit of claim 9 wherein isfurther provided crawler means for initially extending said cross linesunderneath said structure.
 11. The conversion kit of claim 10 whereinsaid crawler means includes a tube through which a cross line passes,spiral thread means on said tube for operative engagement with thebottom of said structure and said ground, and means to rotate said tubeto provide crawling action.
 12. The conversion kit of claim 11 whereinsaid means to rotate comprises a motor, coupling means to connect saidmotor and said tube, and a skid platform for mounting said motor formovement with said tube.
 13. A kit for quick conversion of an immobilestructure to a ground effects machine comprising a flexible skirtcapable of conforming to the outer configuration of said structurearound the periphery thereof, surface-adhering strip means forcontinuous attachment and sealing of the top portion of said skirt tosaid structure, means for holding the lower edge of said skirt injuxtaposition to the ground and directed inwardly to provide a captiveair space defined by the lower portion of said structure and said skirt,and air pressure means for introducing a superatmospheric air supply tosaid space to provide a lifting force for supporting said structure, theinside of said manifold being formed by a flexible wall, said manifoldbeing substantially tear-shaped in cross section when inflated and atleast partially contiguous in sealed relationship with the outer surfaceof said structure, whereby said strip means is isolated from suddenpressure changes in said space and held flat against said surface toresist peeling.
 14. The method of quick conversion of immobile, largeaircraft-size structure to a ground effects machine comprising the stepsof adhering by strip means the upper portion of a flexible skirtdirectly to the outer peripheral surface of said structure, holding saidskirt so that the lower edge of said skirt is in juxtaposition to theground, Whereby to form a captive air space defined by the lower portionof said structure and said skirt, and then pressurizing said space witha superatmospheric air supply to provide a lifting force for supportingsaid structure.
 15. The method of conversion of claim 14 furtherincluding the step of pressurizing the interior of said structurethrough openings in said lower portion communicating with said airspace, and patching any openings in the upper portion of said structureto preclude the escape of air therefrom.
 16. The method of conversion ofclaim 15 wherein the structure is an aircraft and further including thestep of attaching control lines to the wing tie-down points, and moving,balancing and steering said aircraft by tugs attached to said lines. 17.The method of conversion of claim 14 wherein the vehicle is an aircraftand further including the step of obtaining said air supply from the fanportion of a fan jet of said aircraft.
 18. The method of conversion ofclaim 14 wherein the adhering step is performed by applying an adhesivetape.
 19. The method of conversion of claim 18 wherein the step ofapplying the adhesive is performed only by pressure contact.